HDFS-9421. NNThroughputBenchmark replication test NPE with -namenode option. Contributed by Mingliang Liu.

Author: xiaoyuyao

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -2308,6 +2308,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-9387. Fix namenodeUri parameter parsing in NNThroughputBenchmark.
     (Mingliang Liu via xyao)
 
+    HDFS-9421. NNThroughputBenchmark replication test NPE with -namenode option.
+    (Mingliang Liu via xyao)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/NNThroughputBenchmark.java

@@ -106,9 +106,9 @@
  * By default the refresh is never called.</li>
  * <li>-keepResults do not clean up the name-space after execution.</li>
  * <li>-useExisting do not recreate the name-space, use existing data.</li>
- * <li>-namenode will run the test against a namenode in another
- * process or on another host. If you use this option, the namenode
- * must have dfs.namenode.fs-limits.min-block-size set to 16.</li>
+ * <li>-namenode will run the test (except {@link ReplicationStats}) against a
+ * namenode in another process or on another host. If you use this option,
+ * the namenode must have dfs.namenode.fs-limits.min-block-size set to 16.</li>
  * </ol>
  * 
  * The benchmark first generates inputs for each thread so that the
@@ -126,8 +126,9 @@ public class NNThroughputBenchmark implements Tool {
   private static final String GENERAL_OPTIONS_USAGE = 
     "     [-keepResults] | [-logLevel L] | [-UGCacheRefreshCount G] |" +
     " [-namenode <namenode URI>]\n" +
-    "     If using -namenode, set the namenode's" +
-    "         dfs.namenode.fs-limits.min-block-size to 16.";
+    "     If using -namenode, set the namenode's " +
+    "dfs.namenode.fs-limits.min-block-size to 16. Replication test does not " +
+        "support -namenode.";
 
   static Configuration config;
   static NameNode nameNode;
@@ -1471,13 +1472,22 @@ public int run(String[] aArgs) throws Exception {
         ops.add(opStat);
       }
       if(runAll || ReplicationStats.OP_REPLICATION_NAME.equals(type)) {
-        opStat = new ReplicationStats(args);
-        ops.add(opStat);
+        if (namenodeUri != null || args.contains("-namenode")) {
+          LOG.warn("The replication test is ignored as it does not support " +
+              "standalone namenode in another process or on another host. " +
+              "Please run replication test without -namenode argument.");
+        } else {
+          opStat = new ReplicationStats(args);
+          ops.add(opStat);
+        }
       }
       if(runAll || CleanAllStats.OP_CLEAN_NAME.equals(type)) {
         opStat = new CleanAllStats(args);
         ops.add(opStat);
       }
+      if (ops.isEmpty()) {
+        printUsage();
+      }
 
       if (namenodeUri == null) {
         nameNode = NameNode.createNameNode(argv, config);
@@ -1501,8 +1511,6 @@ public int run(String[] aArgs) throws Exception {
             DFSTestUtil.getRefreshUserMappingsProtocolProxy(config, nnUri);
         getBlockPoolId(dfs);
       }
-      if(ops.size() == 0)
-        printUsage();
       // run each benchmark
       for(OperationStatsBase op : ops) {
         LOG.info("Starting benchmark: " + op.getOpName());